在数组中使用随机变量

Question

首先,对不起,如果措辞不好,因为我是代码的初学者.

我目前正在从事在线计算机科学课程,但是我对如何做一小部分非常困惑.我们需要为此活动使用数组,其中用户有多个选择,每个不同的选择具有不同/唯一的文本输出.一切正常,除了我需要一个选择随机选择的选项,但是我对如何制作它有点困惑.您可以从我的代码中看到选项1-8.我希望它随机选择其中一个选项.

这是我的代码:

<?php
$train[0] = "Canada";
$train[1] = "Sahara Desert";
$train[2] = "Russia";
$train[3] = "Chernobyl";
$train[4] = "United States";
$train[5] = "North Korea";
$train[6] = "Germany";
$train[7] = "Hawaii";
?>

<!DOCTYPE html>
<html>
<head>
Took out everything here, it's not important.
</head>

    <body>
        <center>
    <h1>Vacation Time!</h1>

    <h4>You and your family just won the lottery! You all want to go on vacation, but nobody can agree where to go. Inside each train cart has a card with a location written on it. Whatever you find is where you're going! </h4>

        <form name="form1" action="activity-2-7-arrays-a.php" method="post">

            <label>Which cart on the train do you want to choose?</label>
            <br>
            <select name="cart" required>
                <option value="1">First Cart</option>
                <option value="2">Second Cart</option>
                <option value="3">Third Cart</option>
                <option value="4">Fourth Cart</option>
                <option value="5">Fifth Cart</option>
                <option value="6">Sixth Cart</option>
                <option value="7">Seventh Cart</option>
                <option value="8">Eight Cart</option>
                <option value="show">Show all options</option>
                <option value="any">Choose Randomly</option>
                <br>
            </select><br/>
            <input type="submit" name="subButton" class="subButton" value="Go!"/><br/>
            </form>

    <h1><u>Final Results</u></h1>

<?php
if($_POST['subButton']) {
    $cart = $_POST['cart'];
    $roll = rand(1,9);

    if($cart == show) {
        for($x = 1; $x <= 9; $x++) {
            echo "<p> You could have ender up in... </p>";
            echo "<h2> " . $train[$x] . "</h2>";
        }
        return;
    }
    echo "<h2>"."Well, it looks like you're going to " . $train[$cart] . "! Have fun! </h2>";
}
return;

if ($cart == $roll) {

}
echo "<h2>"."Can't handle the pressure? You were selected to go to  " . $train[$roll] . "! Have fun! </h2>";
?>

我也确定它有点乱.希望你明白我的意思.如果你能够向我解释这个非常有用的答案.谢谢 :)

Answer 1

无论用户选择如何，您都会随机生成一个值，并将其与用户的选择和其他奇怪的事情进行比较。

<?php
if($_POST['subButton']) {
    $cart = $_POST['cart'];
    $roll = rand(1,9); 

您甚至在检查用户是否选择“随机选择”之前就生成了一个随机值，为什么要生成 1 到 9 之间的随机值？您的$train数组以索引 0 开始，以索引 7 结束。

    if($cart == show) { 

字符串需要加引号。

        for($x = 1; $x <= 9; $x++) {

由于数组索引的原因，从 1 到 9的循环$x没有任何意义。

            echo "<p> You could have ender up in... </p>";
            echo "<h2> " . $train[$x] . "</h2>";

$x由于上次索引为$train7，达到 8时将失败。

        }
        return;
    } 
    echo "<h2>"."Well, it looks like you're going to " . $train[$cart] . "! Have fun! </h2>";
    }
    return;

因此，如果用户没有选择“显示所有选项”，您会向他显示他选择的位置。如果用户选择“随机选择”，这将失败，因为其$cart值为“任意”并且$train['any']不存在。

这是具有正确逻辑的代码。

<?php
if($_POST['subButton']) {
    $cart = $_POST['cart'];
    if ($cart == 'any') {// Check if user selected 'Choose Randomly'
        $roll = rand(0, 7);
        echo "<h2>"."Can't handle the pressure? You were selected to go to  " .  $train[$roll] . "! Have fun! </h2>";
    }
    else {
        if ($cart == 'show') { // If user selected 'Show all options'
            echo "<p> You could have ender up in... </p>";
            for($x = 0; $x <= 7; $x++) {
                echo "<h2> " . $train[$x] . "</h2>";
            }
        }
        else { // User selected cart so show him chosen location
            echo "<h2>"."Well, it looks like you're going to " . $train[$cart] . "! Have fun! </h2>";
        }
    }
}
?>